This invention relates to a portable power plunger and particularly relates to a plunger which is operative to provide high power for unclogging a blocked drain in sinks, toilets, bath tubs and the like.
Plungers are commonly used for unclogging a blocked drain. The basic plumbing plunger consists of a rubber suction cup or a hollow bell-shaped element attached to an elongated handle. The suction cup or bell-shaped element is pressed over the opening of the drain with a rapid pumping action to create the force required to loosen the blockage. Such simple plungers are not effective for unclogging severe blockage in a drain. For clearing severe blockage, a plumbing cable commonly called a snake may be inserted into the drain to remove the blockage. Plumbing snakes are messy and difficult to use. Alternatively, a power plunger may be employed. A power plunger is shown in U.S. Pat. No. 1,861,899 to J. L. MacMillan in which the plunger includes a hand pump having a rounded outlet lower end for engaging the waste opening of a drain. The pump may be operated for providing the force required to remove the obstruction in the drain. The pump is also provided with an end piece which has a tubular extension at its side. A guide tube, connected to a water supply faucet, can be slidably inserted through the tubular extension into the end piece and extending into the drain until it reaches the blockage to wash the loosen obstruction down the sewer. The main drawback of such power plunger is that there is no provision to prevent the foul water in the drain from backing into the pump housing to contaminate its interior. The device is awkward to operate when the drain is remotely located from the water faucet. In such instance, the operator must run back and forth between the faucet and the clogged drain to adjust the faucet valve during operation in order to obtain the suitable amount of water from the faucet. Also, since the guide tube is only slidably inserted through the side tubular extension, it could easily dislodge from the pump during the vigorous pumping action during operation. Furthermore, since the device must be held firmly pressed against the waste opening by the operator during operation, it would not be possible for the operator to leave the device to walk to the remote faucet to adjust its valve. Doing so would invariably result in the pressurized water from the water supply jetting uncontrollably out of the device to the surrounding area of the drain equipment. Such device is also not suitable for removing a blockage in a toilet, since there is no provision for engaging a toilet drain. U.S. Pat. No. 4,847,923 to C. Huang shows another portable power plunger which is provided with a check valve to prevent the foul water from backing into the pump so as to prevent contamination of the pump. However, the check valve therein is insubstantial in structure such that it would malfunction or clog up easily with particles in the foul water of the drain or break down after a short period of use. Moreover, its outlet is provided with a duct extending beyond a flow guide disc which is intended to cover over the drain opening. Such duct extension would not fit over the majority of the drain opening of common sinks and it could not cover the drain of a toilet to prevent the foul water of the toilet from splashing out therefrom during operation. The Huang device is also provided with a coupling at the handle of the piston stem of the pump so that pressurized water may be injected through the hollow stem into the drain. Such construction is highly impractical, since the connecting tubing would easily dislodge from the coupling at the handle or break at the connection during the vigorous pumping action of the stem during operation.